jack-knife

Fetched 2026-10-26 (cache).

Synonyms: jackknife, jack knife, jacknife

Antonyms: jackknife, jack knife, jacknife

Related words from Datamuse; suggestions, not definitions.

Noun

1. {{senseid|en|knife}} A [[compact]] [[folding knife]].
2. {{senseid|en|pike}} {{lb|en|diving}} The front-dive [[pike]], in which the body folds and unfolds.
3. {{senseid|en|exercise}} {{lb|en|sports}} An [[abdominal]] exercise where knees and torso are raised from a lying position.
4. {{senseid|en|accident}} {{lb|en|road transport|colloquial}} A semi-trailer [[truck]] [[accident]] in which the [[vehicle]] [[mimic]]s the closing of a jack-knife.
5. {{lb|en|games}} A game of skill played with a pocket knife in which participants try to throw or flip the knife to stick upright in the ground at specified points or areas.
6. {{lb|en|statistics}} {{alternative spelling of|en|jackknife}}.

Verb

1. To [[fold]] in the middle, as a [[#Noun|jackknife]] does.
2. {{senseid|en|accident-verb}} {{lb|en|colloquial}} To cause a [[semi-trailer]] [[truck]] to [[fold]] like a [[#Noun|jackknife]] in a traffic accident.

Source: Wiktionary · CC BY-SA 4.0 (Wiktionary dump) · cached copy, not a rewrite.